U.S. patent number 7,750,089 [Application Number 10/598,656] was granted by the patent office on 2010-07-06 for dispersant viscosity modifiers based on diene-containing polymers.
This patent grant is currently assigned to The Lubrizol Corporation. Invention is credited to Michael J. Covitch, Renee A. Eveland, Christopher Friend, Matthew D. Gieselman, Christopher Kolp, Philip Pike, John K. Pudelski.
United States Patent |
7,750,089 |
Kolp , et al. |
July 6, 2010 |
Dispersant viscosity modifiers based on diene-containing
polymers
Abstract
A composition of the reaction product of (a) an
isobutylene-diene copolymer having thereon groups containing
carboxylic acid functionality or reactive equivalent thereof,
derived from an .alpha.,.beta.-unsaturated carboxylic compound; and
(b) an amine component comprising at least one aromatic amine
containing at least one N--H group capable of condensing with said
carboxylic acid functionality, is a useful dispersant viscosity
modifier.
Inventors: |
Kolp; Christopher (Richmond
Heights, OH), Gieselman; Matthew D. (Willoughby Hills,
OH), Eveland; Renee A. (Concord Township, Lake County,
OH), Pike; Philip (Concord Township, Lake County, OH),
Pudelski; John K. (Cleveland Heights, OH), Covitch; Michael
J. (Cleveland Heights, OH), Friend; Christopher
(Bobbersmill, GB) |
Assignee: |
The Lubrizol Corporation
(Wickliffe, OH)
|
Family
ID: |
34961979 |
Appl.
No.: |
10/598,656 |
Filed: |
March 8, 2005 |
PCT
Filed: |
March 08, 2005 |
PCT No.: |
PCT/US2005/007544 |
371(c)(1),(2),(4) Date: |
May 16, 2007 |
PCT
Pub. No.: |
WO2005/087821 |
PCT
Pub. Date: |
September 22, 2005 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20070293409 A1 |
Dec 20, 2007 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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60551838 |
Mar 10, 2004 |
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60569557 |
May 10, 2004 |
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Current U.S.
Class: |
525/374; 525/379;
525/386; 525/382 |
Current CPC
Class: |
C10M
149/06 (20130101); C10M 133/56 (20130101); C08F
8/00 (20130101); C08F 8/32 (20130101); C08F
8/46 (20130101); C10M 159/14 (20130101); C10M
159/126 (20130101); C08F 8/00 (20130101); C08F
210/12 (20130101); C08F 8/32 (20130101); C08F
255/10 (20130101); C08F 8/32 (20130101); C08F
210/10 (20130101); C08F 8/46 (20130101); C08F
210/12 (20130101); C10M 2215/28 (20130101); C10N
2030/02 (20130101); C10M 2217/06 (20130101); C10M
2207/129 (20130101); C10M 2205/06 (20130101); C10M
2215/06 (20130101) |
Current International
Class: |
C08C
19/22 (20060101) |
Field of
Search: |
;525/374,379,382,386 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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0396297 |
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Nov 1990 |
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EP |
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2033907 |
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May 1980 |
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GB |
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0198387 |
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Dec 2001 |
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WO |
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WO 01/98387 |
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Dec 2001 |
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WO |
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2005103093 |
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Nov 2005 |
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WO |
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Primary Examiner: Choi; Ling-Siu
Attorney, Agent or Firm: Shold; David M. Hilker; Christopher
D.
Claims
What is claimed is:
1. A composition comprising the reaction product of: (a) an
isobutylene-diene copolymer having an M.sub.n of about 1000 to
about 150,000 and containing thereon an average of about 0.1 to 4
equivalents, per each 1000 units of M.sub.n of the polymer, of
carboxylic acid functionality or reactive equivalent thereof,
derived from at least one .alpha.,.beta.-unsaturated carboxylic
compound; and (b) an amine component comprising
4-aminodiphenylamine.
2. The composition of claim 1 wherein the diene is selected from
the group consisting of isoprene, piperylene, 1,3-butadiene, and
limonene.
3. The composition of claim 1 wherein the diene comprises
isoprene.
4. The composition of claim 1 wherein (a) the copolymer containing
carboxylic acid functionality is prepared by reacting (i) an
isobutylene-diene copolymer having on average about 1 to about 150
moles of reactive carbon-carbon double bonds per mole of copolymer
and about 0.1 to about 2 moles of said double bonds per 1000 units
of M.sub.n of the copolymer, with (ii) an
.alpha.,.beta.-unsaturated carboxylic compound.
5. The composition of claim 1 wherein the
.alpha.,.beta.-unsaturated carboxylic compound comprises an acrylic
compound, a methacrylic compound, a maleic compound, a fumaric
compound, or an itaconic compound.
6. The composition of claim 1 wherein the
.alpha.,.beta.-unsaturated carboxylic compound comprises maleic
anhydride.
7. The composition of claim 1 wherein the amine component further
comprises an amine having at least two N--H groups capable of
condensing with said carboxylic acid functionality.
8. The composition of claim 7 wherein the amine having at least two
N--H groups comprises ethylenediamine, 2,4-diaminotoluene, or
phenylenediamine.
9. The composition of claim 1 wherein the isobutylene-diene
copolymer has an M.sub.n of 3000 to about 150,000.
10. A lubricant composition comprising a major amount of an oil of
lubricating viscosity and a minor amount of the composition of
claim 1.
11. The lubricant composition of claim 10 further comprising at
least one additive selected from the group consisting of
detergents, dispersants, viscosity modifiers, pour point
depressants, friction modifiers, antioxidants, and antiwear
agents.
12. The lubricant composition prepared by admixing the components
of claim 11.
13. The lubricant composition of claim 10 further comprising a
polyisobutene succinimide dispersant having a N:CO ratio of greater
than about 1.
14. The lubricant composition of claim 10 further comprising a
hydrogenated copolymer of a vinylaromatic monomer with a conjugated
polyene.
15. A process for lubricating an internal combustion engine,
comprising supplying thereto the lubricant of claim 10.
16. A process for improving the viscosity index of a lubricating
oil composition comprising incorporating into said composition a
minor, viscosity-improving amount, of the composition of claim
1.
17. A process for reducing soot-induced viscosity increase in a
lubricating oil composition comprising incorporating into said
composition a minor, viscosity-improving amount, of the composition
of claim 1.
18. A concentrate comprising the composition of claim 1 and a
concentrate-forming amount of an oil of lubricating viscosity.
19. A process for preparing a carboxylic derivative composition,
comprising: (a) reacting (i) an isobutylene-diene copolymer having
an M.sub.n of about 1000 to about 150,000 and having on average
about 0.1 to about 2 units of reactive carbon-carbon double bonds
per each 1000 units of M.sub.n of the polymer, with (ii) an
.alpha.,.beta.-unsaturated carboxylic compound having carboxylic
acid functionality or reactive equivalent thereof; and (b) reacting
the product of (a) with an amine component comprising
4-aminodiphenylamine.
20. The process of claim 19 wherein the .alpha.,.beta.-carboxylic
compound is reacted with the isobutylene-diene polymer via a
thermal reaction in the substantial absence of added chlorine.
21. The process of claim 19 wherein the .alpha.,.beta.-carboxylic
compound is reacted with the isobutylene-diene polymer via a
radical reaction.
22. The process of claim 19 wherein the amine component of (b)
further comprises an amine having at least two N--H groups capable
of condensing with said carboxylic acid functionality.
23. A composition comprising the reaction product of: (a) an
isobutylene-diene copolymer having an M.sub.n of about 1000 to
about 150,000 and containing thereon an average of about 0.1 to 4
equivalents, per each 1000 units of M.sub.n of the polymer, of
carboxylic acid functionality or reactive equivalent thereof,
derived from at least one .alpha.,.beta.-unsaturated carboxylic
compound; and (b) an amine component comprising 3-nitroaniline.
Description
BACKGROUND OF THE INVENTION
The present invention relates to dispersants for use in fuels and
in engine oil lubricants, especially for reducing soot-induced
viscosity increase in heavy duty diesel engines.
Heavy duty diesel vehicles may use exhaust gas recirculation (EGR)
engines in efforts to reduce environmental emissions. Among the
consequences of recirculating the exhaust gas through the engine
are different soot structures and increased viscosity of the oil at
lower soot levels, compared with engines without EGR. It is
desirable that oil exhibit minimal viscosity increase, e.g., less
than 12 mm.sup.2/sec (cSt) at a soot loading of 6%. A material that
attenuates viscosity increase typically disperses soot up to high
soot loading.
It is also desirable that a lubricating oil composition maintain a
relatively stable viscosity over a wide range of temperatures.
Viscosity improvers are often used to reduce the extent of the
decrease in viscosity as the temperature is raised or to reduce the
extent of the increase in viscosity as the temperature is lowered,
or both. Thus, a viscosity improver ameliorates the change of
viscosity of an oil containing it with changes in temperature. The
fluidity characteristics of the oil are improved.
Traditional dispersant viscosity modifiers (DVMs) made from
ethylene-propylene copolymers that have been radically grafted with
maleic anhydride and reacted with various amines have shown
desirable dispersant performance. Aromatic amines are said to show
good performance in this regard. DVMs of this type are disclosed in
U.S. Pat. No. 4,863,623, Nalesnik et al., Sep. 5, 1989, as well as
U.S. Pat. Nos. 6,107,257, Valcho et al., and 6,107,258, Esche et
al., each Aug. 22, 2000, and U.S. Pat. No. 6,117,825, Liu et al.,
Sep. 12, 2000.
Other polymer backbones have also been used for preparing
dispersants. For example, polymers derived from isobutylene and
isoprene ("IOB/IP") have been used in preparing dispersants and are
reported in WO 01/98387. The present invention provides a
dispersant viscosity modifier based on a polymer of isobutylene and
a diene such as isoprene which is, however, distinguished from such
earlier dispersants by means of, among other things, the molecular
weight of the polymer backbone and, generally, the selection of the
significantly different amine component, leading to a significantly
different polymeric structure. The present materials exhibit
superior performance in engine tests. Moreover, the synthesis of
the present materials, based upon isobutylene and a diene typically
is significantly simpler and less costly than the synthesis of
ethylene/propylene copolymers. Typically only a single catalyst is
required, and extremely flammable hydrogen gas is not required as a
chain terminator. The polymers in question have the advantage of
providing olefin unsaturation and thus being suitable for further
functionalization with or without a catalyst or solvent.
The present invention, therefore, solves the problem of providing a
low cost dispersant viscosity modifier having improved performance
in engine tests, providing a good viscosity index and good soot
dispersion and toleration properties, particularly in diesel
engine, and especially in heavy duty diesel engines employing
exhaust gas recirculation.
SUMMARY OF THE INVENTION
Therefore, the present invention provides a composition comprising
the reaction product of:
(a) an isobutylene-diene copolymer having an M.sub.n of 1000 to
150,000 and containing thereon an average of 0.1 to 4 equivalents,
per each 1000 units of M.sub.n of the polymer, of carboxylic acid
functionality or reactive equivalent thereof, derived from at least
one .alpha.,.beta.-unsaturated carboxylic compound; and
(b) an amine component comprising at least one aromatic amine
containing at least one N--H group capable of condensing with said
carboxylic acid functionality.
The invention also provides lubricants and lubricant concentrates
comprising the foregoing reaction product and an oil of lubricating
viscosity, as well as a method for lubricating an internal
combustion engine by supplying the same thereto.
The invention also provides A process for preparing a carboxylic
derivative composition, comprising:
(a) reacting (i) an isobutylene-diene copolymer having an M.sub.n
of 1000 to 150,000 and having on average 0.1 to 2 units of reactive
carbon-carbon double bonds per each 1000 units of M.sub.n of the
polymer, with (ii) an .alpha.,.beta.-unsaturated carboxylic
compound having carboxylic acid functionality or reactive
equivalent thereof; and
(b) reacting the product of (a) with an amine component comprising
at least one aromatic amine containing at least one N--H group
capable of condensing with said carboxylic acid functionality.
The invention also provides a process for improving the viscosity
index of a lubricating oil composition, comprising incorporating
into said composition a minor, viscosity-improving amount, of the
composition as described herein.
DETAILED DESCRIPTION OF THE INVENTION
Various preferred features and embodiments will be described below
by way of non-limiting illustration.
As used herein, the term "hydrocarbyl substituent" or "hydrocarbyl
group" is used in its ordinary sense, which is well-known to those
skilled in the art. Specifically, it refers to a group having a
carbon atom directly attached to the remainder of the molecule and
having predominantly hydrocarbon character. Examples of hydrocarbyl
groups include:
hydrocarbon substituents, that is, aliphatic (e.g., alkyl or
alkenyl), alicyclic (e.g., cycloalkyl, cycloalkenyl) substituents,
and aromatic-, aliphatic-, and alicyclic-substituted aromatic
substituents, as well as cyclic substituents wherein the ring is
completed through another portion of the molecule (e.g., two
substituents together form a ring);
substituted hydrocarbon substituents, that is, substituents
containing non-hydrocarbon groups which, in the context of this
invention, do not alter the predominantly hydrocarbon nature of the
substituent (e.g., halo (especially chloro and fluoro), hydroxy,
alkoxy, mercapto, alkylmercapto, nitro, nitroso, and sulfoxy);
hetero substituents, that is, substituents which, while having a
predominantly hydrocarbon character, in the context of this
invention, contain other than carbon in a ring or chain otherwise
composed of carbon atoms. Heteroatoms include sulfur, oxygen,
nitrogen, and encompass substituents as pyridyl, furyl, thienyl and
imidazolyl. In general, no more than two, preferably no more than
one, non-hydrocarbon substituent will be present for every ten
carbon atoms in the hydrocarbyl group; typically, there will be no
non-hydrocarbon substituents in the hydrocarbyl group.
The Copolymer
The compositions of the present invention are derived from
isobutylene-diene copolymers having M.sub.n of 1000 to 150,000,
alternatively 1000 to 100,000, or 1000 to 50,000, or 1000 to
25,000, or 2000 to 18,000, or 3000 to 16,000. A mole of copolymer
is defined herein as the M.sub.n or number average molecular weight
of the copolymer, expressed in grams. Molecular weights of the
copolymers are determined using well known methods described in the
literature. Examples of procedures for determining molecular
weights are gel permeation chromatography (GPC), light scattering,
and vapor phase osmometry (VPO). The GPC technique is calibrated
using well-characterized polymers against which the samples are
compared. For best results, standards that are chemically similar
to those of the sample are used. For example, for polystyrene
polymers, a polystyrene standard, preferably of similar molecular
weight, is employed. When standards are chemically dissimilar to
the sample, generally relative molecular weights of related
polymers can be determined. For example, using a polystyrene
standard, relative, but not absolute, molecular weights of a series
of polyalkylmethacrylates may be determined. For the present
materials, polyisobutylene standards are preferably used.
Copolymers of this invention can be prepared employing cationic
polymerization catalysts. Lewis acids are particularly preferred
catalysts. These include metal halides, for example AlCl.sub.3,
BF.sub.3, SnCl.sub.4, SbCl.sub.5, ZnCl.sub.2, TiCl.sub.4, and
PCl.sub.5, organometallic derivatives, for example RAlCl.sub.2,
R.sub.2AlCl, R.sub.3Al, where R is a hydrocarbon group, and
oxyhalides, for example POCl.sub.3, CrO.sub.2Cl, SOCl.sub.2, and
VOCl.sub.3. Suitable catalysts include aluminum compounds such as
AlCl.sub.3, AlEtCl.sub.2 and AlEt.sub.2Cl, where Et is ethyl.
Initiation by Lewis acids requires or tends to proceed faster in
the presence of a proton donor such as water, hydrogen halide,
alcohol and carboxylic acid or a carbocation donor such as t-butyl
chloride or triphenylmethyl fluoride. Alternatively, copolymers of
the desired molecular weight can be prepared from corresponding
butyl rubber compounds of higher molecular weight, by shearing them
an appropriate high shear device such as an extruder. Butyl rubbers
and their preparation are well known and are disclosed, e.g., in
Kresge et al., "Isobutyl Polymers," Ency. Polym. Sci. Eng. (1987)
8, 423-48.
Copolymers are defined herein as polymers derived from at least two
different monomers. Thus, copolymers include polymers derived from,
for example, 2, 3, 4 or more different monomers, more often 2 or 3
different monomers. Accordingly, copolymers of the instant
invention are derived from isobutylene and at least one diene which
may have conjugated or isolated (non-conjugated) double bonds. More
often the polyenes are conjugated dienes. Suitable dienes include
isoprene, piperylene (1,3-pentadiene), 1,3-butadiene, and limonene
(dipentene, or p-mentha-1,8-diene, optically active or inactive).
Terpolymers derived from isobutylene, isoprene and 1,3-butadiene
are useful. Other dienes that can be present include,
methylisoprene, dicyclopentadiene, 1,4-pentadiene,
2,3-dimethyl-1,3-butadiene, trans-2-methyl-1,3-pentadiene,
cyclopentadiene, 1,5-hexadiene, 2,4-hexadiene,
2,5-dimethyl-2,4-hexadiene, 1,5-heptadiene, 1,7-octadiene, and
5-ethylidene-2-norbornene. Triene can also be present, such as
1,3,5-cycloheptatriene, 2,6-dimethyl-2,4,6-octatriene, myrcene,
1-iso-propylidene-3a,4,7,7a-tetrahydroindene, 1-isopropylidene- and
2-(2-methylene-4-methyl-3-pentenyl)[2.2.1]bicyclo-5-heptene and
higher polyenes such as cyclooctatetraene. Both cis and trans
isomers can be used.
The copolymer typically contains 0.1 to 4 or 0.1 to 2 units derived
from diene per 1000 M.sub.n of the polymer, or alternatively 0.15
to 1.0 units per 1000 M.sub.n. This means that, for instance, a
polymer of 2000 M.sub.n could contain 0.2 to 4 diene-derived units,
a polymer of 25,000 could contain 2.5 to 50 units, on average, and
so on. Of course, polymers should normally contain on average at
least 1 diene unit per polymer chain, since it would not normally
be desirable to have a significant fraction of the polymer chains
without the additional reactive site provided by the diene monomer.
As otherwise expressed, the copolymer can comprise, for instance,
an average of 1 to 150, or 1 to 100, or 1 to 50, or 1 to 30, or 1
to 25, or 1 to 12, or 1 to 10 moles, frequently 1.5 or 2 to 8
moles, of units derived from diene, per mole based on M.sub.n of
copolymer, the actual amount, of course, depending to some extent
on the M.sub.n of the copolymer. The copolymer (prior to reaction
with the unsaturated carboxylic compound) typically contains a
corresponding number of reactive carbon to carbon double bonds per
mole thereof. The term "reactive" in this context means that the
double bond is capable of reacting with and adding to the
carbon-carbon double bond of the unsaturated carboxylic compounds
under conditions as described below. It is-observed that under
certain conditions, especially for the thermal or "ene" reaction,
not all the double bonds in the copolymer are reactive; perhaps
70-97% or 80-95% of the double bonds will be reactive. While not
wishing to be bound by theory, it is believed that, in order to
assure suitable reactivity with unsaturated carboxylic compounds
such as maleic anhydride under such conditions, it may be desirable
that the diene such as isoprene be predominantly incorporated in a
1,4 addition. The amount of 1,4 versus 1,2 incorporation can be
determined by .sup.1H NMR.
The isobutylene-polyene copolymers of this invention permit greater
flexibility in the design of the polymer and ultimately,
derivatives thereof. The use of more than one monomer permits the
design of a polymer having particularly desired properties.
Polymerizations can be conducted at temperatures of -90 or
-78.degree. C. to 50.degree. C.; more commonly -50.degree. C. to
-15.degree. C. or to 0.degree. C. Generally lower temperatures lead
to higher molecular weight polymer. Reaction pressures range from
about atmospheric to 345 kPa gauge (50 pounds per square inch,
gauge [psig]), preferably 55 to 117 kPa gauge (8 to about 17 psig).
The reactivity of the diene towards copolymerization with
isobutylene determines the amount charged relative to isobutylene.
When the reactivity of the diene is similar to the reactivity of
isobutylene, the mole ratio of polyene charged is similar to that
incorporated into the polymer; if it is less reactive, the amount
incorporated may be less. For example, in the case of isoprene, a
relative mole ratio of 9% leads to about 2.3% isoprene incorporated
into the copolymer as determined by .sup.1H NMR. For dienes having
reactivities much less than that of isobutylene, the mole ratio of
polyene charged is considerably greater than the amount of polyene
incorporated into the polymer, often 20 times greater, and
sometimes even more. Dry solvents are frequently used during the
polymerizations. Solvents can solubilize the polymer and provide a
means for controlling the reaction temperature. Reaction times
usually depend on the scale of the reaction and the amount of
cooling that can be delivered to the reactor. The reaction can be
quenched with methanol, water or dilute caustic solution, and
washed with water. Then solvents and light ends, including
lower-boiling by-products are removed by stripping, usually at
elevated temperature and reduced pressure.
.alpha.,.beta.-Unsaturated Carboxylic Compound
The carboxylic derivative compositions of this invention are
prepared from carboxylated isobutylene-diene, copolymers.
Carboxylation is effected by reacting the copolymer with at least
one .alpha.,.beta.-unsaturated carboxylic compound or reactive
equivalent thereof. The carboxylated copolymer typically contains
0.1 to 4 or 0.1 to 2 equivalents of unsaturated carboxylic acid
functionality per each 1000 units of M.sub.n of the polymer, or
0.15 to 1 unit per each 1000 units of M.sub.n, as described above
for the number of diene units in the polymer. Thus, just as
described above, there can be, in certain embodiments, 1 to 50 or 1
to 30 or 1 to 25 or 1 to 12, or 1.5 to 10 moles, per mole of
copolymer, of groups containing carboxylic acid functionality or
reactive equivalent thereof, said groups derived from at least one
(.alpha.,.beta.-unsaturated carboxylic compound.
A reactive equivalent of an .alpha.,.beta.-unsaturated carboxylic
compound is a reactant that will react in a fashion similar to a
carboxylic acid to form derivatives that are essentially the same
as those obtained from the carboxylic acid. For example,
anhydrides, lower alkyl esters, and acyl halides will react with
amines to form substantially similar products as will the
corresponding acids. Anhydrides, lower alkyl esters and acyl
halides are all considered to be reactive equivalents to the
corresponding acid.
The .alpha.,.beta.-ethylenically unsaturated carboxylic acids and
reactive equivalents thereof are well known in the art. The most
commonly used materials contain two to 20 carbon atoms exclusive of
carbonyl carbons. These include such acids as acrylic acid,
methacrylic acid, maleic acid, fumaric acid, crotonic acid,
citraconic acid, itaconic acid and mesaconic acid, as well as their
anhydrides, halides and esters (especially the lower alkyl esters,
the term "lower alkyl" meaning alkyl groups having up to 7 carbon
atoms). Preferred are acrylic compounds, maleic compounds, fumaric
compounds and itaconic compounds, in which context the term
"compounds" is intended to refer to the acids and reactive
equivalents thereof as described herein. Especially preferred
compounds are the .alpha.,.beta.-olefinically unsaturated
carboxylic acids, especially those containing at least two carboxy
groups and more preferably dicarboxylic acids, and their
derivatives. Maleic acid and maleic anhydride, especially the
latter, are particularly suitable. Maleic compounds and other
materials bearing two vicinal carboxy groups are to be counted as
contributing two equivalents of carboxylic acid functionality.
In order to minimize the amount of chlorine present in the
carboxylic derivatives of this invention, it is sometimes desirable
to avoid the use of chlorine or chlorine containing reactants,
promoters, or catalysts. Accordingly, in one embodiment, the
carboxylated copolymer is prepared by a thermal reaction wherein
the copolymer and the alpha-beta-olefinic carboxylic acids or
reactive equivalents thereof are reacted by simply combining and
heating the reactants at an elevated temperature, usually from
150.degree. C. to 250, or to 240, or to 230.degree. C., preferably
from about 180.degree. C. The thermal reaction can be conducted
without addition of any catalyst or initiator, avoiding the
possible need for its subsequent removal. The time for the reaction
can be 4-6 hours, or up to 24 hours, or as otherwise will be
apparent to the person skilled in the art. The reaction can be
conducted in a stirred vessel or in an extruder under known
conditions.
Preparation of products of the present invention via the so-called
"thermal" route may be seen as analogous in terms of processing
steps to the known preparation of conventional dispersant by a
thermal process. As disclosed in the literature, it is known that
relatively high vinylidene polyisobutylene can be prepared,
typically by use of a BF.sub.3 catalyst, and subsequently reacted
with maleic anhydride. The reaction occurs in the absence of
chlorine catalyst by a series of thermal "ene" reactions to produce
a mixture of mono- and poly-succininated dispersant material.
Preparation of conventional acylating agents from polyisobutylene
made from a BF.sub.3 process and their reaction with amines is
disclosed in U.S. Pat. No. 4,152,499. Similar adducts are known,
based on polymers other than polyisobutylene. For instance U.S.
Pat. No. 5,275,747 discloses derivatized ethylene alpha-olefin
polymers with terminal ethenylidene unsaturation which can be
substituted with mono- or dicarboxylic acid producing moieties.
In an alternative process, the present grafted copolymers can be
prepared by a radical reaction, that is, by radically grafting the
unsaturated carboxylic compound onto a chain of the
isobutylene-diene polymer in a stirred vessel in the presence or
absence of solvent or in an extruder, typically in the presence of
an additional free radical initiator to provide a randomly grafted
product. Suitable free radical initiators are well known materials,
including peroxy-containing materials. The polymer may also be
subjected to high shear as a result of the extrusion process,
leading to polymer chains of reduced molecular weight. Such a
grafting process is disclosed, for instance, in U.S. Pat. No.
3,862,265.
The amount of carboxylic compound reacted with the polymer is in
certain instances less than or equal to, on an equivalent basis,
the amount of reactive double bonds within the polymer. It may be
desirable to avoid the presence of excess acid material, which may
need to be subsequently removed, although an excess may be supplied
if a more complete conversion is desired. Also, when a radical
grafting process is employed, amounts of carboxylic compound may be
employed in excess of the amount of initially present reactive
double bonds, e.g., up to 1.1, or 1.2 or 1.5 equivalents.
Aromatic Amine
The carboxylic derivative compositions of this invention are
obtained by reacting the carboxylated copolymer with an aromatic
amine containing at least one, and preferably exactly one, N--H
group capable of condensing with said carboxylic acid
functionality, to form nitrogen-containing carboxylic derivatives
of the present invention which contain dispersant functionality.
Aromatic amines include those which can be represented by the
general structure NH.sub.2--Ar, where Ar is an aromatic group,
including nitrogen-containing aromatic groups and Ar groups
including any of the following structures
##STR00001## as well as multiple non-condensed aromatic rings. In
these and related structures, R.sub.4, R.sub.5, and R.sub.6 can be
independently, among other groups disclosed herein, --H,
--C.sub.1-18 alkyl groups, --NH--Ar, --N.dbd.N--Ar, --NH--CO--Ar,
--OOC--Ar, --OOC--C.sub.1-18 alkyl, --COO--C.sub.1-18 alkyl, --OH,
--O--(CH.sub.2CH.sub.2--O).sub.nC.sub.1-18 alkyl groups,
--NO.sub.2, and --O--(CH.sub.2CH.sub.2O)Ar (where n is 0 to
10).
Aromatic amines include but are not limited to those amines wherein
a carbon atom of the aromatic ring structure is attached directly
to the amino nitrogen. The amines may be monoamines or polyamines.
The aromatic ring will typically be a mononuclear aromatic ring
(i.e., one derived from benzene) but can include fused aromatic
rings, especially those derived from naphthalene. Examples of
aromatic amines include aniline, N-alkylanilines such as N-methyl
aniline, and N-butylaniline, di-(para-methylphenyl)amine,
naphthylamine, 4-aminodiphenylamine, N,N-dimethylphenylenediamine,
4-(4-nitrophenylazo)aniline (disperse orange 3), sulfamethazine,
4-phenoxyaniline, 3-nitroaniline, 4-aminoacetanilide
4-amino-2-hydroxy-benzoic acid phenyl ester (phenyl amino
salicylate), N-(4-amino-5-methoxy-2-methyl-phenyl)-benzamide (fast
violet B), N-(4-amino-2,5-dimethoxy-phenyl)-benzamide (fast blue
RR), N-(4-amino-2,5-diethoxy-phenyl)-benzamide (fast blue BB),
N-(4-amino-phenyl)-benzamide and 4-phenylazoaniline. Other examples
include para-ethoxyaniline, para-dodecylaniline,
cyclohexyl-substituted naphthylamine, and thienyl-substituted
aniline. Examples of other suitable aromatic amines include
amino-substituted aromatic compounds and amines in which the amine
nitrogen is a part of an aromatic ring, such as 3-aminoquinoline,
5-aminoquinoline, and 8-aminoquinoline. Also included are aromatic
amines such as 2-aminobenzimidazole, which contains one secondary
amino group attached directly to the aromatic ring and a primary
amino group attached to the imidazole ring. Other amines include
N-(4-anilinophenyl)-3-aminobutanamide (i.e.,
.phi.-NH-.phi.-NH--COCH.sub.2CH(CH.sub.3)NH.sub.2). Additional
aromatic amines and related compounds are disclosed in U.S. Pat.
Nos. 4,863,623, 6,107,257, and 6,107,258; some of these include
aminocarbazoles, aminoindoles, aminopyrroles, aminoindazolinones,
aminoperimidines, mercaptotriazoles, aminophenothiazines,
aminopyridiens, aminopyrazines, aminopyrimidines, pyridines,
pyrazines, pyrimidines, aminothiadiazoles, aminothiothiadiazoles,
and aminobenzotriaozles. Other suitable amines include
3-amino-N-(4-anilinophenyl)-N-isopropyl butanamide, and
N-(4-anilinophenyl)-3-{(3-aminopropyl)-(cocoalkyl)amino}butanamide.
Other aromatic amines which can be used include various aromatic
amine dye intermediates containing multiple aromatic rings linked
by, for example, amide structures. Examples include materials of
the general structure
##STR00002## and isomeric variations thereof, where R.sup.1 and
R.sup.2 are independently hydrogen, alkyl groups, or alkoxy groups
such as methyl, methoxy, or ethoxy. In one instance, R.sup.1 and
R.sup.2 are both --OCH.sub.3 and the material is known as Fast Blue
RR [CAS#6268-05-9]. In another instance, R.sup.1 is --OCH.sub.3 and
R.sup.2 is --CH.sub.3, and the material is known as Fast Violet B
[99-21-8]. When both R.sup.1 and R.sup.2 are ethoxy, the material
is Fast Blue BB [120-00-3]. U.S. Pat. No. 5,744,429 discloses other
aromatic amine compounds, particularly aminoalkylphenothiazines.
N-aromatic substituted acid amide compounds, such as those
disclosed in U.S. Patent application 2003/0030033 A1, may also be
used for the purposes of this invention. Preferred aromatic amines
include those in which the amine nitrogen is a substituent on an
aromatic carboxylic compound, that is, the nitrogen is not sp.sup.2
hybridized within an aromatic ring. The aromatic amine will
preferably have an N--H group capable of condensing with a
carboxylic acid acylating agent.
Certain aromatic amines are commonly used as antioxidants. Of
particular importance in that regard are alkylated diphenylamines
such as nonyldiphenylamine and dinonyldiphenylamine. To the extent
that these materials will condense with the carboxylic
functionality of the polymer chain, they are also suitable for use
within the present invention. However, it is believed that the two
aromatic groups attached to the amine nitrogen may lead to steric
hindrance and reduced reactivity. Thus, preferred amines are those
having a primary nitrogen atom (--NH.sub.2) or a secondary nitrogen
atom in which one of the hydrocarbyl substituents is a relatively
short chain alkyl group, e.g., methyl. Among preferred aromatic
amines are 4-phenylazoaniline, 4-aminodiphenylamine,
2-aminobenzimidazole, 3-nitroaniline, 4-(4-nitrophenylazo)aniline
(disperse orange 3),
N-(4-amino-5-methoxy-2-methyl-phenyl)-benzamide (fast violet B),
N-(4-amino-2,5-dimethoxy-phenyl)-benzamide (fast blue RR),
N-(4-amino-2,5-diethoxy-phenyl)-benzamide (fast blue BB),
N-(4-amino-phenyl)-benzamide, and N,N-dimethylphenylenediamine.
The above-described aromatic amines can be used alone or in
combination with each other. They can also be used in combination
with additional, aromatic or non-aromatic, e.g., aliphatic, amines,
which, in one embodiment, comprise 1 to 8 carbon atoms. These
additional amines can be included for a variety of reasons.
Sometimes it may be desirable to incorporate an aliphatic amine in
order to assure complete reaction of the acid functionality of the
polymer, in the event that some residual acid functionality may
tend to react incompletely with a relatively more bulky aromatic
amine. Alternatively, an aliphatic amine may replace a portion of a
more costly aromatic amine, while maintaining the majority of the
performance of the aromatic amine. Aliphatic monoamines include
methylamine, ethylamine, propylamine and various higher amines.
Diamines or polyamines can be used for this function, provided
that, in general, they have only a single reactive amino group,
that is, a primary or secondary, and preferably primary, group.
Suitable examples of such diamines include
dimethylaminopropylamine, diethylaminopropylamine,
dibutylaminopropylamine, dimethylaminoethylamine,
diethylaminoethylamine, dibutylaminoethylamine,
1-(2-aminoethyl)piperidine, 1-(2-aminoethyl)pyrrolidone,
aminoethylmorpholine, and aminopropylmorpholine. The amount of such
an amine is typically a minor amount compared with the amount of
the aromatic amine, that is, less than 50% of the total amine
present on a weight or molar basis, although higher amounts can be
used. Exemplary amounts include 10 to 70 weight percent, or 15 to
50 weight percent, or 20 to 40 weight percent.
In one embodiment of the invention, the amine component of the
reaction product further comprises an amine having at least two
N--H groups capable of condensing with said carboxylic acid
functionality (that is, two or more reactive groups). This material
is referred to hereinafter as a "linking amine" as it can be
employed to link together two of the polymers containing the
carboxylic acid functionality. Such products exhibit even more
superior soot-handling performance. The linking amine can be either
an aliphatic amine or an aromatic amine; if it is an aromatic
amine, it is considered to be in addition to and a distinct element
from the aromatic amine described above, which need have and
preferably should have only one condensable or reactive NH group,
in order to avoid excessive crosslinking of the polymer chains.
Examples of such linking amines include ethylene diamine,
2,4-diaminotoluene and phenylene diamine; others include propylene
diamine, hexamethylene diamine, and other
.alpha.,.beta.-polyalkylenediamines.
Other specific means of linkage of an aromatic amine onto the
carboxy-containing interpolymer are also contemplated as included
within the scope of the invention by the expression "the reaction
product of an isobutylene-diene copolymer and an amine component."
For example, amine functionality can be introduced into the polymer
by including an amine-containing comonomer in the reaction mixture
when the interpolymer is grafted. The amine-containing comonomer
can be the reaction or condensation product of an amine with the
alpha, beta-unsaturated acylating agent described above. For
instance, the condensation product of maleic anhydride and an
aromatic amine such as 4-aminodiphenylamine or 4-phenylazoaniline
can be employed. The latter materials is known and bears the CAS
number [16201-96-0]. It is believed to have the structure
##STR00003## (including geometric and positional isomers thereof).
Similarly, the adduct with 4-aminodiphenylamine and methods of its
preparation are reported in U.S. Patent Application Publication
2004/0043909; see for instance Example 1 on page 15.
In another example of such an alternative route, a hydroxyamide can
be esterified with the carboxy groups on the polymer chain.
Exemplary hydroxyamides can be represented by HO--R--CO--NH--Ar
and
##STR00004## where the Ar is an aromatic moiety of the aromatic
amine (which may contain additional nitrogen or other
functionality) and R is an alkylene or hydrocarbylene linking
group. Alternatively, a hydroxyacid can be first esterified with a
carboxy group on the interpolymer and thereafter reacted with an
aromatic amine; in either case the hydroxyacid serves as a linking
group between the polymer chain and the aromatic amine.
The total amount of the amine condensed onto the carboxylic acid
functionality of the polymer is preferably about 1 equivalent of
reactive amine functionality per equivalent of
.alpha.,.beta.-unsaturated carboxy compound on the polymer chain as
described above. If more than a stoichiometric amount is used,
excess amine may remain and may need to be removed from the
product. If less than a stoichiometric amount is used, residual
unreacted acid or anhydride functionality may remain in the polymer
which may likewise be undesirable. If a diamine is used in addition
to an aromatic monoamine, the diamine can be present in an amount
of 1 mole (that is, 2 equivalents) of condensable amine
functionality per 5 to 6 moles of carboxy compound on the polymer
chain. Thus, the diamine can be 1 mole (2 equivalents) per 4 to 5
moles of aromatic monoamine. It is desirable that any linking amine
be used in an amount such that the anhydrides (or carboxy
materials) on any given polymer chain react with an amine nitrogen
from only one linking amine molecule, so as to minimize the
likelihood of gelling of the polymer.
The carboxylic derivative compositions produced by reacting the
carboxylated copolymers of the invention and the amines described
above are acylated amines which include amine salts, amides, imides
and imidazolines as well as mixtures thereof. To prepare the
carboxylic derivative compositions from the amines, one or more of
the carboxylated copolymers and one or more amines can be heated,
optionally in the presence of a normally liquid, substantially
inert organic liquid solvent/diluent, at temperatures of 80.degree.
C. up to the decomposition point of any of the reactants or the
product, but normally at temperatures of 100.degree. C. to
300.degree. C., provided 300.degree. C. does not exceed the
decomposition point of a reactant or the product. Temperatures of
125.degree. C. to 250.degree. C. are commonly used. If more than
one amine is used, the amines can be added and reacted in either
order, or simultaneously. The carboxylic composition and the amine
are reacted in an amount sufficient to provide from about one-half
equivalent up to two moles of amine per equivalent of the
carboxylic composition. In another embodiment, the carboxylic
composition is reacted with from about one-half equivalent up to
one mole of amine per equivalent of the carboxylic composition. For
the purpose of this invention, an equivalent of amine is that
amount of amine corresponding to the total weight of amine divided
by the total number of condensable nitrogens present having
H--N<groups. Thus, octyl amine has an equivalent weight equal to
its molecular weight; ethylenediamine has an equivalent weight
equal to one-half its molecular weight, and aminoethylpiperazine,
with 3 nitrogen atoms but only two having at least one
H--N<group, has an equivalent weight equal to one-half of its
molecular weight.
The Oil of Lubricating Viscosity
The lubricating compositions of this invention employ an oil of
lubricating viscosity, including natural or synthetic lubricating
oils and mixtures thereof. Natural oils include animal oils and
vegetable oils (e.g. castor oil, lard oil) as well as mineral
lubricating oils such as liquid petroleum oils and solvent-treated
or acid treated mineral lubricating oils of the paraffinic,
naphthenic or mixed paraffinic-naphthenic types. Oils of
lubricating viscosity derived from coal or shale are also useful.
Synthetic lubricating oils include hydrocarbon oils and
halosubstituted hydrocarbon oils such as polymerized and
interpolymerized olefins and mixtures thereof, alkylbenzenes,
polyphenyl, (e.g., biphenyls, terphenyls, alkylated polyphenyls),
alkylated diphenyl ethers and alkylated diphenyl sulfides and the
derivatives, analogs and homologues thereof. Alkylene oxide
polymers and interpolymers and derivatives thereof where their
terminal hydroxyl groups have been modified by esterification,
etherification, etc., constitute another useful class of known
synthetic lubricating oils. Another suitable class of synthetic
lubricating oils comprises the esters of di- and poly-carboxylic
acids and those made from C.sub.5 to C.sub.20 monocarboxylic acids
and polyols and polyolethers. Other synthetic lubricating oils
include liquid esters of phosphorus-containing acids, polymeric
tetrahydrofurans and the like, silicon-based oils such as the
polyalkyl-, polyaryl-, polyalkoxy-, or polyaryloxy-siloxane oils
and silicate oils. Synthetic oils also include those produced by a
gas-to-liquid or Fischer-Tropsch process.
Unrefined, refined and rerefined oils, either natural or synthetic
(as well as mixtures of two or more of any of these) of the type
disclosed hereinabove can be used in the compositions of the
present invention. Unrefined oils are those obtained directly from
natural or synthetic sources without further purification
treatment. Refined oils are similar to the unrefined oils except
they have been further treated in one or more purification steps to
improve one or more properties. Refined oils include solvent
refined oils, hydrorefined oils, hydrofinished oils, hydrotreated
oils, and oils obtained by hydrocracking and hydroisomerization
techniques.
Oils of lubricating viscosity can also be defined as specified in
the American Petroleum Institute (API) Base Oil Interchangeability
Guidelines. The five base oil groups are as follows:
TABLE-US-00001 Base Oil Category Sulfur (%) Saturates (%) Viscosity
Index Group I >0.03 and/or <90 80-120 Group II <0.03 and
>90 80-120 Group III <0.03 and >90 >120 Group IV All
polyalphaolefins (PAOs) Group V All others not included in Groups
I, II, III, or IV
Groups I, II, and III are mineral oil base stocks. Group III base
oils are also sometimes considered to be synthetic base oils. Other
Additives
The lubricating oil compositions of this invention may contain
other components. The use of such additives is optional and the
presence thereof in the compositions of this invention will depend
on the particular use and level of performance required. Thus the
other additive may be included or excluded. The compositions may
comprise a metal salt, frequently a zinc salt of a dithiophosphoric
acid. Zinc salts of dithiophosphoric acids are often referred to as
zinc dithiophosphates or zinc O,O'-dihydrocarbyl dithiophosphates
and are sometimes referred to by the abbreviations ZDP, ZDDP, or
ZDTP. One or more zinc salts of dithiophosphoric acids may be
present in a minor amount to provide additional extreme pressure,
anti-wear and anti-oxidancy performance. Other metal salts of
dithiophosphoric acids, such as copper, antimony, etc. salts are
known and may be included in the lubricating oil compositions of
this invention.
Other additives that may optionally be used in the lubricating oils
of this invention include detergents, dispersants, viscosity
improvers, oxidation inhibiting agents (antioxidants), pour point
depressing agents, extreme pressure agents, friction modifiers,
anti-wear agents, color stabilizers and anti-foam agents. The
above-mentioned dispersants and viscosity improvers may be used in
addition to the compositions of this invention.
Auxiliary extreme pressure agents and corrosion and oxidation
inhibiting agents which may be included in the compositions of the
invention are exemplified by chlorinated aliphatic hydrocarbons,
organic sulfides and polysulfides, phosphorus esters including
dihydrocarbon and trihydrocarbon phosphites, molybdenum compounds,
and the like.
Auxiliary viscosity improvers (also sometimes referred to as
viscosity index improvers or viscosity modifiers) may be included
in the compositions of this invention. Viscosity improvers are
usually polymers, including polyisobutenes, polymethacrylic acid
esters, diene polymers, polyalkyl styrenes, esterified
styrene-maleic anhydride copolymers, alkenylarene-conjugated diene
copolymers (that is, vinylarene-conjugated polyene copolymers and
hydrogenated copolymers of this type, such as hydrogenated
styrene-butadiene copolymers), and polyolefins. Multifunctional
viscosity improvers, other than those of the present invention,
which also have dispersant and/or antioxidancy properties are known
and may optionally be used in addition to the products of this
invention.
Detergents are typically overbased materials. Overbased materials,
otherwise referred to as overbased or superbased salts, are
generally homogeneous Newtonian systems characterized by a metal
content in excess of that which would be present for neutralization
according to the stoichiometry of the metal and the particular
acidic organic compound reacted with the metal. The overbased
materials are prepared by reacting an acidic material (typically an
inorganic acid or lower carboxylic acid, preferably carbon dioxide)
with a mixture comprising an acidic organic compound, a reaction
medium comprising at least one inert, organic solvent (mineral oil,
naphtha, toluene, xylene, etc.) for said acidic organic material, a
stoichiometric excess of a metal base, and a promoter such as a
phenol or alcohol. The acidic organic material will normally have a
sufficient number of carbon atoms to provide a degree of solubility
in oil. The amount of excess metal is commonly expressed in terms
of metal ratio. The term "metal ratio" is the ratio of the total
equivalents of the metal to the equivalents of the acidic organic
compound. A neutral metal salt has a metal ratio of one. A salt
having 4.5 times as much metal as present in a normal salt will
have metal excess of 3.5 equivalents, or a ratio of 4.5.
Such overbased materials are well known to those skilled in the
art. Patents describing techniques for making basic salts of
sulfonic acids, carboxylic acids, phenols, phosphonic acids, and
mixtures of any two or more of these include U.S. Pat. Nos.
2,501,731; 2,616,905; 2,616,911; 2,616,925; 2,777,874; 3,256,186;
3,384,585; 3,365,396; 3,320,162; 3,318,809; 3,488,284; and
3,629,109.
Dispersants are well known in the field of lubricants and include
primarily what is known as ashless-type dispersants. Ashless type
dispersants are characterized by a polar group attached to a
relatively high molecular weight hydrocarbon chain. Typical ashless
dispersants include N-substituted long chain alkenyl succinimides,
having a variety of chemical structures including typically
##STR00005## where each R.sup.1 is independently an alkyl group
(which may bear more than one succinimide group), frequently a
polyisobutyl group with a molecular weight of 500-5000 (and the
corresponding dispersant is thus a polyisobutene succinimide), and
R.sup.2 are alkylene groups, commonly ethylene (C.sub.2H.sub.4)
groups. Such molecules are commonly derived from reaction of an
alkenyl acylating agent with a polyamine, and a wide variety of
linkages between the two moieties is possible beside the simple
imide structure shown above, including a variety of amides and
quaternary ammonium salts. Succinimide dispersants are more fully
described in U.S. Pat. Nos. 4,234,435 and 3,172,892. Particularly
useful succinimide dispersants are those having a N:CO ratio of
greater than about 1, that is, with overall excess nitrogen
functionality derived from the polyamine, compared with the
carbonyl functionality derived from the succinic acid groups. Such
materials may also be described as high nitrogen dispersants,
containing at least 1.6% or at least 2% nitrogen in the dispersant
(on an active chemical, oil-free basis) and having a relatively
high total base number (TBN) of at least 30, 40, or even 50 (mg
equivalent KOH per gram of sample, active chemical basis).
Desirable materials are also relatively high molecular weight
dispersants, having, for instance alkyl or hydrocarbyl (polymer)
groups with M.sub.n of greater than 1300.
Another class of ashless dispersant is high molecular weight
esters. These materials are similar to the above-described
succinimides except that they may be seen as having been prepared
by reaction of a hydrocarbyl acylating agent and a polyhydric
aliphatic alcohol such as glycerol, pentaerythritol, or sorbitol.
Such materials are described in more detail in U.S. Pat. No.
3,381,022.
Another class of ashless dispersant is Mannich bases. These are
materials which are formed by the condensation of a higher
molecular weight, alkyl substituted phenol, an alkylene polyamine,
and an aldehyde such as formaldehyde. Such materials may have the
general structure
##STR00006## (including a variety of isomers and the like) and are
described in more detail in U.S. Pat. No. 3,634,515.
Other dispersants include polymeric dispersant additives, which are
generally hydrocarbon-based polymers which contain polar
functionality to impart dispersancy characteristics to the
polymer.
Dispersants can also be post-treated by reaction with any of a
variety of agents. Among these are urea, thiourea,
dimercaptothiadiazoles, carbon disulfide, aldehydes, ketones,
carboxylic acids, hydrocarbon-substituted succinic anhydrides,
nitrites, epoxides, boron compounds, and phosphorus compounds.
References detailing such treatment are listed in U.S. Pat. No.
4,654,403.
The above-illustrated additives may each be present in lubricating
compositions at a concentration of as little as 0.001% by weight,
usually 0.01% to 20% by weight. In most instances, they each
contribute 0.1% to 10% by weight, more often up to 5% by
weight.
Additive Concentrates
The various additives described herein can be added directly to the
lubricant. Preferably, however, they are diluted with a
concentrate-forming amount of a substantially inert, normally
liquid organic diluent such as mineral oil or a synthetic oil such
as a polyalphaolefin to form an additive concentrate. These
concentrates usually comprise 0.1 to 80% by weight of the
compositions of this invention and may contain, in addition, one or
more other additives known in the art or described hereinabove.
Concentrations such as 15%, 20%, 30% or 50% of the additives or
higher may be employed. By a "concentrate forming amount" is
generally mean an amount of oil or other solvent less than the
amount present in a fully formulated lubricant, e.g., less than 85%
or 80% or 70% or 60%. Additive concentrates can be prepared by
mixing together the desired components, often at elevated
temperatures, usually up to 150.degree. C. or 130.degree. C. or
115.degree. C.
Lubricating Oil Compositions
The instant invention also relates to lubricating oil compositions
containing the carboxylic compositions of the invention. The amount
of polymer contained in a fully formulated lubricant is typically
0.1 to 10% by weight, alternatively 0.5 to 6% or 1 to 3% by weight.
As noted hereinabove, the compositions of this invention may be
blended directly into an oil or lubricating viscosity or, more
often, are incorporated into an additive concentrate containing one
or more other additives which in turn is blended into the oil.
It is known that some of the materials described above may interact
in the final formulation, so that the components of the final
formulation may be different from those that are initially added.
For instance, metal ions (of, e.g., a detergent) can migrate to
other acidic or anionic sites of other molecules. The products
formed thereby, including the products formed upon employing the
composition of the present invention in its intended use, may not
be susceptible of easy description. Nevertheless, all such
modifications and reaction products are included within the scope
of the present invention; the present invention encompasses the
composition prepared by admixing the components described
above.
EXAMPLES
Example 1
Isobutylene, isoprene, hexane, and AlCl.sub.3 are charged to a 1 L
continuous reactor. Solid AlCl.sub.3 is added to promote
polymerization of the monomers. The reaction mixture is maintained
at -30.degree. C. by external cooling. Over seven hours, 7056 g
isobutylene, 858 g isoprene, 11,780 mL hexanes, and 17.3 g
AlCl.sub.3 are charged to the reaction vessel.
Product leaving the reactor is quenched by dropping into a mixture
of hexanes, methanol and water. The organic layer is washed with
distilled water, dried with magnesium sulfate, filtered,
concentrated in vacuo and stripped at 205.degree. C. at 133 Pa (1
mm Hg). The yield of copolymer is 2450 g. M.sub.n (GPC vs.
polyisobutylene standards) is 6900. By .sup.1H NMR, 1
isoprene-derived monomer unit is present in 1000 molecular weight
units of the polymer.
Example 2
A copolymer is prepared analogously to the polymer in example 1.
Over ten hours, 10,080 g isobutylene, 915 g isoprene, 16,420 mL
hexanes, and 13 g AlCl.sub.3 are charged to the reaction vessel.
The yield of copolymer is 3429 g. M.sub.n (GPC vs. polyisobutylene
standards) is 8200. By .sup.1H NMR, 1 isoprene-derived monomer unit
is present in 1300 molecular weight units of the polymer.
Examples 3-6
Four copolymers are prepared analogously using different catalysts
and different temperatures.
TABLE-US-00002 Example 3 Example 4 Example 5 Example 6 Isobutylene,
g 7056 3024 7056 8064 Isoprene, g 643 274 643 733 Hexane, g 7700
3300 7700 9600 Catalyst, g 7 3 7 10 Identity of catalyst
EtAlCl.sub.2 EtAlCl.sub.2 AlCl.sub.3 AlCl.sub.3 Reaction temp.,
.degree. C. -30 -50 -50 -32 Reaction time, hr 7 3 7 8 Yield of
copolymer, g 1500 587 1500 2742 M.sub.n of copolymer 11,400 13,800
14,000 12,750 Molecular Wt. per 1500 1153 1074 1784
isoprene-derived monomer unit
Example 7
The copolymer from example 1 (2450 g) and maleic anhydride (88 g)
are heated at 203.degree. C. for 24 hours with stirring under a
blanket of N.sub.2 and are blown with N.sub.2 for 30 minutes at 14
L/hr (0.5 SCFH). The resulting hydrocarbyl-substituted acylating
agent has a Total Acid Number (TAN) of 38 and 0.7 wt. % unreacted
maleic anhydride.
Examples 8-10
Three hydrocarbyl-substituted acylating agents are prepared
according to the procedure of Example 7 using copolymer of Example
2.
TABLE-US-00003 Example 8 Example 9 Example 10 Copolymer, g 725 2048
650 Maleic anhydride, g 16 57 29 TAN 24 29 40 Unreacted maleic
anhydride, wt % 0.07 0.08 0.16
Examples 11-12
Two hydrocarbyl-substituted acylating agents are prepared according
to the procedure of Example 7 using the copolymers of Examples
3-4.
TABLE-US-00004 Example 11 Example 12 Identity of copolymer Example
3 Example 4 Copolymer, g 1600 586 Maleic anhydride, g 63 25 TAN 39
40 TAN after oil dilution (50%) 21 22 Unreacted maleic anhydride,
wt % 0.19 0.2
Example 13
The copolymer from example 6 (403 g) and maleic anhydride (22 g)
are heated to 160.degree. C. with stirring under a blanket of
N.sub.2 14 L/hr (0.5 SCFH). T-butyl peroxide (4 g) is charged to a
dropping funnel and added drop-wise over 2.5 hr. The preparation is
stirred for an additional 30 min at 160.degree. C., and the sample
is purged with N.sub.2 57 L/hr (2.0 SCFH) at 190.degree. C. The
resulting hydrocarbyl-substituted acylating agent has a Total Acid
Number (TAN) of 46 and 0.2 wt. % unreacted maleic anhydride.
Example 14
A dispersant viscosity modifier is prepared by diluting 175 g of
the hydrocarbyl-substituted acylating agent of Example 7 with 393 g
diluent oil. Then 11 g 4-aminodiphenylamine is added at 110.degree.
C. over 30 minutes followed by heating at 160.degree. C. for 4
hours. The product is obtained by filtration through a pad of
diatomaceous earth. Yield is 548 g. Percent nitrogen is 0.29.
Kinematic viscosity at 100.degree. C.=98 (KV100, ASTM
D445.sub.--100).
Examples 15-17
Three dispersant viscosity modifiers are prepared by the method of
Example 14 using the hydrocarbyl-substituted acylating agents of
Examples 8-10.
TABLE-US-00005 Example 15 Example 16 Example 17 Acylating agent:
source Example 8 Example 9 Example 10 amount, g 680 990 618 Oil, g
1497 2195 1390 Aminodiphenylamine, g 27 48 40 Yield 2105 3074 1963
% nitrogen 0.17 0.19 0.33 KV 100 94 96 124
Example 18
A dispersant viscosity modifier is prepared by diluting 1026 g of
acylating agent of Example 9 with 2241 g of diluent oil. To this
mixture at 50.degree. C. is added 3 g of ethylenediamine dropwise
over the course of two hours. The resulting mixture is warmed to
110.degree. C. and 30 g 4-aminodiphenylamine is added portion-wise
over ten minutes. The resulting mixture is stirred at 110.degree.
C. for one hour and then at 160.degree. C. for nine hours. The
product is filtered using diatomaceous earth. Yield is 3119 g.
Percent nitrogen is 0.22. KV 100 is 177.
Example 19
A dispersant viscosity modifier is prepared by diluting 374 g of
the acylating agent from Example 13 with 852 g of diluent oil. To
this mixture at 110.degree. C. is added 28 g of
4-aminodiphenylamine over the course of 30 min. The resulting
mixture is warmed to 160.degree. C. and stirred for 5 hr. The
product is filtered using diatomaceous earth. Yield is 1205 g.
Percent nitrogen is 0.29. KV 100 is 159.
A soot screen test is performed on several of the experimental
samples prepared above. In this test, the candidate chemistry is
added to an oil sample from the end of a test drain from a Mack.TM.
T-11 engine. The sample is subjected to oscillation and the ability
of the candidate to reduce the buildup of associations between
molecules of soot is measured as a modulus, by a method described
in SAE Paper 2001-01-1967, "Understanding Soot Mediated Oil
Thickening: Rotational Rheology Techniques to Determine Viscosity
and Soot Structure in Peugot XUD-11 BTE Drain Oils," M. Parry, H.
George, and J. Edgar, presented at International Spring Fuels &
Lubricants Meeting & Exhibition, Orlando, Fla., May 7-9, 2001.
The calculated parameter is referred to as G'. The G' of the sample
treated with the experimental chemistry is compared to the G' of
the drain oil without the additive, the latter of which is defined
as 1.00. Values of G' less than 1.00 indicate increasing
effectiveness at soot dispersion.
TABLE-US-00006 G' Table Ex. 20 Ex. 21 Ex. 22 Ex. 23 Ex. 24 Ex. 25
Dispersant ID Ex. 14 Ex. 15 Ex. 16 Ex. 17 Ex. 18 Ex. 19 1% disp.
0.33 0.55 0.47 0.16 0.25 0.16 2% disp. 0.17 0.34 0.31 0.09 0.11
0.04
Examples 26-28
Three lubricant formulations are prepared and are subjected to the
Mack.TM. T-11 test. In this test a sample of lubricant is run in a
Mack.TM. T-11 for up to 252 hours. Over time, as soot is
accumulated in the oil, samples are withdrawn and their kinematic
viscosity is measured at 100.degree. C. Results are reported as
viscosity increase in mm.sup.2/s (cSt).
Example 26 (reference) is a baseline contains oil and a commercial
composition including an olefin copolymer viscosity modifier,
detergent(s), overbased calcium detergent(s), phenolic
antioxidant(s), a corrosion inhibitor, and other conventional
components. Example 27 (reference) is substantially the same
formulation but contains 2.6% of a succinimide dispersant with a
polyisobutylene/isoprene substituent (not corrected for diluent
oil; 1.17% active chemical in the lubricant). Example 28 is
substantially the same formulation but containing 3.1% of the
dispersant viscosity modifier of the present invention, (as in
Example 27, not corrected; providing 1.0% active chemical in the
lubricant), and the amount of conventional viscosity modifier
reduced by a comparable amount.
The viscosity increase for each of the samples, as a function of
time and soot buildup, is shown in the following table:
TABLE-US-00007 Example 27 (ref) Example 28 Example 26 (ref)
Baseline + IOB/IP Baseline + IOB/IP Baseline dispersant
dispersant/VM Viscosity Viscosity Viscosity time, wt % increase, wt
% increase, wt % increase, hr. Soot mm.sup.2/s (cSt) Soot
mm.sup.2/s (cSt) Soot mm.sup.2/s (cSt) 0 0.16 0.00 0.21 0.00 0.15
1.92 12 0.44 0.00 0.61 0.00 0.59 1.51 24 0.67 0.00 0.80 0.00 0.80
1.41 36 0.98 0.00 1.09 0.00 1.02 1.42 48 1.35 0.02 1.53 0.08 1.32
1.40 60 1.66 0.06 1.79 0.11 1.59 1.50 72 1.95 0.30 2.11 0.15 1.92
1.60 84 2.36 0.45 2.44 0.37 2.26 1.84 96 2.75 0.72 2.79 0.55 2.55
2.02 108 3.10 1.12 3.06 0.77 2.89 2.27 120 3.47 1.64 3.46 1.11 3.37
2.72 132 3.83 2.20 3.80 1.61 3.70 2.99 144 4.17 3.13 4.17 2.15 3.99
3.45 156 4.52 4.72 4.47 2.71 4.27 4.17 168 4.84 7.82 4.78 3.54 4.59
4.61 180 5.21 16.55 5.03 5.00 4.84 5.44 192 5.69 35.66 5.43 7.54
5.17 6.33 204 6.14 53.12 5.76 17.30 5.48 7.11 216 6.21 139.66 5.92
28.92 5.88 9.88 228 6.66 6.26 43.35 6.28 14.24 240 7.09 6.54 47.21
6.53 29.43 252 7.58 6.96 71.46 6.84 50.29
The results in the table show that the baseline material exhibits a
significant rise in viscosity beginning at about a 4% soot level
(144 hours). The baseline+dispersant material of Example 27
exhibits a gradual increase and a significant upward break at
around 5.5% soot level (192 hours). The inventive material of
Example 28 also exhibits gradual increase and a significant upward
break at around 6% soot level (216 hours). (The non-zero values for
viscosity increase for Example 28 at low soot levels are considered
to be of no significance and may be subtracted from the subsequent
values in this table.) The results show that the materials of the
present invention are effective at dispersing soot in this diesel
engine test.
Each of the documents referred to above is incorporated herein by
reference. Except in the Examples, or where otherwise explicitly
indicated, all numerical quantities in this description specifying
amounts of materials, reaction conditions, molecular weights,
number of carbon atoms, and the like, are to be understood as
modified by the word "about." Unless otherwise indicated, each
chemical or composition referred to herein should be interpreted as
being a commercial grade material which may contain the isomers,
by-products, derivatives, and other such materials which are
normally understood to be present in the commercial grade. However,
the amount of each chemical component is presented exclusive of any
solvent or diluent oil, which may be customarily present in the
commercial material, unless otherwise indicated. It is to be
understood that the upper and lower amount, range, and ratio limits
set forth herein may be independently combined. Similarly, the
ranges and amounts for each element of the invention can be used
together with ranges or amounts for any of the other elements. As
used herein, the expression "consisting essentially of" permits the
inclusion of substances that do not materially affect the basic and
novel characteristics of the composition under consideration.
* * * * *